In a known prior art device of this general kind as shown, for example, in German Pat. Publication Application No. 1,761,792, the conveyor means at the filling station is swingable into a downwardly inclined position in response to the arrival of an envelope at the filling station. On completion of an envelope stuffing operation, and in response to a setting device, the conveyor means is pivoted in the opposite direction so as to provide a downwardly inclined transport for conveying the stuffed envelope from the filling station in the same direction in which the envelope was transported to the filling station. This opposite position of inclination of the conveyor means for discharging the envelope from the filling station relies on the weight of the envelope, conveyed with its flap at the lead edge, for movement of the envelope by gravity from the inclined conveyor means to a pair of rollers for closing and sealing the flap of the envelope. However, because the envelope is conveyed with the flap thereof facing upwardly and at the lead edge, in order to close the flap against the body of the envelope prior to a flap sealing operation, the prior art device additionally resorts to an air blast for moving the envelope flap towards a closed position.
In this prior device, as a result of the air blast acting against the stuffed envelope on the inclined conveyor means the envelope will, at times, be held against movement on the inclined conveyor means by the air blast applied to the envelope. In other instances, while the envelope may not be held against movement, the air blast often retards discharge of the stuffed envelope from the conveyor means thereby slowing down and disturbing the machine operation as a whole. Moreover, since the envelope is fed with the flap at its lead end and the flap only is gripped to hold the envelope for a stuffing operation at the filling station, and because the flimsy and limp nature of the flap does not lend itself to positive gripping action, the envelope may be improperly positioned or shifted out of position at the filling station thereby further hampering proper operation of the machine.